Datasheet LT3668 (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | 40V 400mA Step-Down Switching Regulator with Dual Fault Protected Tracking LDOs |
| Pages / Page | 28 / 6 — TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. … |
| File Format / Size | PDF / 386 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Minimum Switch On-Time/. Switch Current Limit
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LT3668
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Minimum Switch On-Time/ Switch Current Limit Switching Frequency Switch-Off Time
900 2.4 200 LOAD CURRENT = 200mA 2.2 RT = 37.4k 180 2.0 800 160 0% DUTY CYCLE 1.8 MINIMUM OFF-TIME 1.6 140 700 1.4 120 MINIMUM ON-TIME 1.2 R 100 T = 95.3k 600 1.0 100% DUTY CYCLE 80 FREQUENCY (MHz) 0.8 60 0.6 SWITCH CURRENT LIMIT (mA) 500 40 0.4 R CATCH DIODE VALLEY CURRENT LIMIT T = 487k 0.2 SWITCH ON-TIME/SWITCH OFF-TIME (ns) 20 400 0 0 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3668 G10 3668 G11 3668 G12
Minimum Input Voltage, Switch VCESAT BOOST Pin Current VOUT1 = 3.3V
600 20 5.0 FRONT PAGE APPLICATION 18 VEN = VIN1, VOUT1 = 3.3V 500 16 4.5 (V) 400 14 (mV) IN1 TO START 4.0 12 CESAT 300 TO RUN 10 3.5 200 8 SWITCH V TJ = –50°C BOOST PIN CURRENT (mA) 6 INPUT VOLTAGE V 3.0 100 TJ = 25°C TA = 150°C TJ = 125°C 4 TA = 25°C TJ = 150°C TA = –50°C 0 2 3.5 0 100 200 300 400 500 600 700 0 100 200 300 400 500 600 0 50 100 150 200 250 300 350 400 SWITCH CURRENT (mA) SWITCH CURRENT (mA) LOAD CURRENT IOUT1 (mA) 3668 G13 3668 G14 3668 G15
Minimum Input Voltage, Transient Load Response, Transient Load Response VOUT1 = 6V Load Step 10mA to 140mA Load Step 150mA to 300mA
7.5 FRONT PAGE APPLICATION FRONT PAGE APPLICATION 7.0 TO START VOUT1 VOUT1 (V) 100mV/DIV 100mV/DIV IN1 6.5 TO RUN 6.0 IL IL INPUT VOLTAGE V 100mA/DIV 150mA/DIV 5.5 FRONT PAGE APPLICATION VEN = VIN1, VOUT1 = 6V 5.0 0 50 100 150 200 250 300 350 400 3668 G17 100µs/DIV 3668 G18 100µs/DIV LOAD CURRENT IOUT1 (mA) 3668 G16 3668fa 6 For more information www.linear.com/LT3668 Document Outline Features Applications Description Typical Application Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Minimum Switch On-Time/ Switch Current Limit Switching Frequency Switch-Off Time
900 2.4 200 LOAD CURRENT = 200mA 2.2 RT = 37.4k 180 2.0 800 160 0% DUTY CYCLE 1.8 MINIMUM OFF-TIME 1.6 140 700 1.4 120 MINIMUM ON-TIME 1.2 R 100 T = 95.3k 600 1.0 100% DUTY CYCLE 80 FREQUENCY (MHz) 0.8 60 0.6 SWITCH CURRENT LIMIT (mA) 500 40 0.4 R CATCH DIODE VALLEY CURRENT LIMIT T = 487k 0.2 SWITCH ON-TIME/SWITCH OFF-TIME (ns) 20 400 0 0 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3668 G10 3668 G11 3668 G12
Minimum Input Voltage, Switch VCESAT BOOST Pin Current VOUT1 = 3.3V
600 20 5.0 FRONT PAGE APPLICATION 18 VEN = VIN1, VOUT1 = 3.3V 500 16 4.5 (V) 400 14 (mV) IN1 TO START 4.0 12 CESAT 300 TO RUN 10 3.5 200 8 SWITCH V TJ = –50°C BOOST PIN CURRENT (mA) 6 INPUT VOLTAGE V 3.0 100 TJ = 25°C TA = 150°C TJ = 125°C 4 TA = 25°C TJ = 150°C TA = –50°C 0 2 3.5 0 100 200 300 400 500 600 700 0 100 200 300 400 500 600 0 50 100 150 200 250 300 350 400 SWITCH CURRENT (mA) SWITCH CURRENT (mA) LOAD CURRENT IOUT1 (mA) 3668 G13 3668 G14 3668 G15
Minimum Input Voltage, Transient Load Response, Transient Load Response VOUT1 = 6V Load Step 10mA to 140mA Load Step 150mA to 300mA
7.5 FRONT PAGE APPLICATION FRONT PAGE APPLICATION 7.0 TO START VOUT1 VOUT1 (V) 100mV/DIV 100mV/DIV IN1 6.5 TO RUN 6.0 IL IL INPUT VOLTAGE V 100mA/DIV 150mA/DIV 5.5 FRONT PAGE APPLICATION VEN = VIN1, VOUT1 = 6V 5.0 0 50 100 150 200 250 300 350 400 3668 G17 100µs/DIV 3668 G18 100µs/DIV LOAD CURRENT IOUT1 (mA) 3668 G16 3668fa 6 For more information www.linear.com/LT3668 Document Outline Features Applications Description Typical Application Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts
